If you fly to Chicago right now in Google Earth with the 3D Buildings layer turned on, you will find that there are two John Hancock buildings in the layer. And, one of them isn’t even in the right spot (the one with the white antennas). Not sure how the second one slipped in, but this wouldn’t be the first time 3D model errors slipped in. You have to give Google credit – with millions of 3D models being added to the 3D Warehouse, it’s hard to make sure only the correct data gets into the layer. See for example the giant building (actually a model conversion bug) found last year – but, was fixed shortly thereafter.